Recently new catalysts have been developed which are far more active than conventional catalysts in the polymerization of alpha-olefins. Briefly described, these catalysts are comprised of a titanium halide catalyst component supported on magnesium dihalide and an alkylaluminum compound, which can be present as a complex with an electron donor compound. These catalyst components have been described in the patent literature, e.g., in U.S. Pat. Nos. 3,830,787, 3,953,414, 4,051,313, 4,115,319, 4,149,990, 4,218,339, 4,220,554, 4,226,741 and 4,263,169.
Catalysts of these types function well in the homo and copolymerization of alpha-olefins having from 2 to 18 carbon atoms particularly when the process is carried out under slurry conditions using a liquid hydrocarbon diluent, which can be liquid monomer, inert hydrocarbon or a mixture of such compounds.
The productivities obtained with these new catalysts are extremely high resulting in polymers containing such small quantities of residual catalyst that the conventional deashing step can be dispensed with.
Further improvements in overall process economics have been achieved by the use of spherical or spheroidal-shaped supported titanium halide catalyst compounds in slurry polymerizations of alpha-olefins. The polymer produced under such conditions is in the shape of free-flowing beads obviating the need for melt extruding the polymer into pellets before shipment of the product to the user. One disadvantage, however, of eliminating the melt extrusion step is that it becomes extremely difficult to homogenously incorporate any of the various additives that may be a desired component of the final polymer product without resorting to a compounded master batch technique, which is expensive.
It is, therefore, an object of the present invention to provide a novel additive-containing polymer product in bead form.
Another object of the invention is to provide a process for the production of an additive-containing polymer in bead form.